Missile Datcom is a Fortran 90 compatible code for preliminary missile aerodynamic design. McDonnell Douglas originally developed it for the Air Force in the early '80s. There after it was updated and maintained by various individuals at AFRL/VA, Wright-Paterson AFB in Ohio. The last "official" release of the code was in 3/99 and subsequently is no longer supported by the Air Force.

Missile Datcom is a government restricted release code and is not considered freeware or shareware. It used to be available from the Air Force to other government agencies and approved DOD contractors. It is also export controlled.

While there are a number of companies / individuals who still have / use the code, there is currently no "official" designated government source for the code that I am aware of. Given the original distribution restrictions on the code I would be surprised if any legitimate user would openly provide a copy.

As an alternate, if cost is not an issue, you can now buy AP2005 from Frank Moore of Aeroprediction Inc. The AP 2005 code is an enhanced version of the AP98 code, which was the Navy's equivalent of Missile Datcom.